This invention relates to an irradiation system with an ion beam/charged particle beam and, in particular, relates to an energy filter for use therein.
An irradiation system with an ion beam/charged particle beam (also called an ion implantation system; hereinafter referred to simply as a “irradiation system with a beam”) is a system for applying a mass analysis to ions or charged particles extracted from a beam source to thereby select only a necessary ion species or necessary charged particles and irradiating a wafer with the beam.
Among this type of irradiation systems with the beam, there is available one having, in addition to a mass analyzer, an energy filter called an angular energy filter (AEF) in order to more accurately implant ions or charged particles into a wafer.
The angular energy filter applies a magnetic field or an electric field to an ion beam/charged particle beam passing therethrough to deflect it by a Lorentz force so as to irradiate the wafer with only those ions or charged particles each having a predetermined energy.
The conventional irradiation system with ion beam/charged particle beam comprises, as the angular energy filter, either a deflection magnet for producing a magnetic field or deflection electrodes for producing an electric field depending on the intended use (irradiation conditions etc.). For example, the system comprising the deflection electrodes is disclosed in JP-A-2003-288857.
The conventional irradiation system with ion beam/charged particle beam comprises, as the energy filter, either a deflection magnet for producing a dipole magnetic field or deflection electrodes for producing an dipole electric field. Therefore, there is a problem that the conventional irradiation system with ion beam/charged particle beam is limited in its use (beam conditions etc.).